Such devices are well known. The print head is formed by a ceramic plate associated with a metal radiator which is mounted on a frame to tilt or pivot about an axis parallel to the axis of the capstan, which is itself carried by the frame in bearings or half-bearings, either permanently if the printer is not openable, or else temporarily, solely when the printer is closed. A spring loaded between the frame and the print head presses the print head against a generator line of the capstan via its row of hot points situated in the vicinity of the edge of the plate opposite from its edge close to the tilt axis.
Friction between the print head and the paper traveling under its row of hot points generates electrostatic charge which accumulates in the head and which needs to be removed in order to avoid the charge disturbing print quality. Other charge can also be transferred to the head, as occurs in particular during contact between the head and the hand of an operator who happens to be carrying charge.
Electrical power and control of the hot points of the print head are provided via a flat conductor (ribbon cable) which also includes a ground conductor. This conductor serves in particular to connect the print head to the ground of the printer or of the apparatus in which the printer is included. Electrical contact between the print head and the ground wire of the ribbon cable is provided by any suitable means, for example a screw terminal installed in the radiator and onto which there is engaged a conductive eyelet that is electrically connected to the ground wire and that is held in place by a nut screwed onto the terminal. That type of assembly is lengthy and expensive to perform.